Two-wheel bag transporting trolley capable of being converted into four-wheel trolley

Abstract

Described herein is a two-wheeled bag transport cart convertible into a four-wheeled cart, comprising a main frame having a pick-up shovel at the foot end and two running wheels on the side opposite the pick-up shovel, an auxiliary frame having a displacement guide for the auxiliary frame, and a link between the main frame and the auxiliary frame, the auxiliary frame supports a steering wheel in the foot region, the displacement guide device can pivot at the handle end of the main frame around a pivot axis parallel to the axis of the running wheel, and the connecting rod is hinged to the main frame in the foot region of the main frame around an axis parallel to the pivot axis. In order to ensure advantageous operating conditions, it is proposed that the auxiliary frame is freely slidably guided in a displacement guide between two stop-limited end positions, one of which determines a two-wheeled bag transport trolley state and the other determines a four-wheeled trolley state, and the connecting rod is fixedly and pivotally supported on the main frame.

Description

TECHNICAL FIELD

[0001] The invention relates to a two-wheeled bag trolley which can be converted into a four-wheeled trolley, comprising a main frame, an auxiliary frame, displacement guide means for the auxiliary frame and a connecting link between the main frame and the auxiliary frame, the main frame having a picking shovel at the foot end and two running wheels on the side opposite the picking shovel, the auxiliary frame having at least one steering wheel supported in the foot region, the displacement guide means being pivotable at the handle end of the main frame about a pivot axis parallel to the axis of the running wheels, the connecting link being hinged to the main frame in the foot region of the main frame about an axis parallel to the pivot axis. BACKGROUND

[0002] In order to simply convert a two-wheeled bag trolley into a four-wheeled trolley, it is known (US 10 864 933 B2) to provide the main frame at the handle end with an auxiliary frame which is pivotable about a pivot axis parallel to the axis of the running wheels and is supported slidably in the longitudinal direction, so that the auxiliary frame remains in a stationary position pivoted inwards relative to the main frame in the two-wheeled bag trolley state with the stop limit, in which the steering wheel provided in the foot region of the auxiliary frame is located unused above the running wheels of the main frame. However, if the auxiliary frame is pivoted outwards from the stationary position to a pivoted position extending transversely to the main frame and pulled out relative to the main frame to the working position with the stop limit, the steering wheel of the auxiliary frame, which is now located in the handle end region of the main frame below, is used, while the longer section of the auxiliary frame is used as a handle section for guiding the four-wheeled trolley, which protrudes upwards in the trolley function from the main frame forming a substantially horizontal support platform. However, it is disadvantageous that, due to the freely slidable nature of the auxiliary frame between the two end positions, the handling is made difficult, since there is a risk of uncontrolled pivoting and sliding displacement of the two frames relative to one another as a result of the force of gravity when one of the two frames is loosened.

[0003] In order to utilize the intermediate position formed when a two-wheeled sack carrier is converted into a four-wheeled sack carrier, in which intermediate position the main frame forms a support platform which is inclined with respect to the ground, (US 6 364 328 B1) it is known to articulate a displacement guide for the auxiliary frame at the handle end of the main frame, in the foot region a link is articulated to the auxiliary frame about an axis which is parallel to the pivot axis of the displacement guide. The link is guided slidably in parallel to the main frame at the opposite end and can be locked with respect to the main frame in predetermined sliding positions. Since the displacement guide is provided with locking means, the auxiliary frame can be fixed in different sliding positions, so that by means of the link which is held immovably with respect to the main frame and the auxiliary frame, which is held immovably respectively but pivotably with respect to the main frame, a triangular connection can be formed between the main frame and the auxiliary frame, which triangular connection provides stable conditions for the two working positions of the sack carrier. In addition to the additional structural outlay associated with the intermediate position of the sack carrier, the mutual conversion operation between the two-wheeled sack carrier and the four-wheeled sack carrier must again be regarded as disadvantageous, since the required displacement between the main frame and the auxiliary frame can only be carried out in a specific sequence and after specific locking or unlocking steps. SUMMARY

[0004] The technical problem addressed by the present application is therefore to design a two-wheeled sack carrier which can be converted into a four-wheeled sack carrier in such a way that the conversion can be carried out in a simple manner without the need to follow predetermined operating steps.

[0005] The technical problem addressed by the present application is therefore to design a two-wheeled sack carrier which can be converted into a four-wheeled sack carrier in such a way that the conversion can be carried out in a simple manner without the need to follow predetermined operating steps.

[0006] By the linkage articulated position-fixed on both frames, a forced guidance of the auxiliary frame relative to the main frame is ensured, which prevents uncontrolled movements when converting the two-wheeled bag trolley into the four-wheeled trolley. If starting from the two-wheeled bag trolley state, after releasing the locking between the auxiliary frame and the main frame, the auxiliary frame is pivoted away from the main frame at the handle end of the main frame about its pivot axis, wherein, due to the effect of gravity, a balanced position of the auxiliary frame results from each tilting position of the main frame, which is determined by the triangle formed by the articulation point of the linkage and the pivot axes between the auxiliary frame and the main frame. The weight load of the auxiliary frame generates a gravitational torque on the linkage, which prevents the outward pivoting of the auxiliary frame. This also means that, when the steering wheels of the auxiliary frame are resting on the ground, the auxiliary frame cannot pivot outward relative to the main frame beyond the ground normal, so that no torque arises which would cause the auxiliary frame to pivot uncontrolled away from the main frame to the end position of the stop limit for the four-wheeled trolley operation. For this purpose, the main frame needs to be lowered further, but preferably the upward protrusion of the auxiliary frame from the handle section of the main frame is adjusted accordingly. In order to convert the four-wheeled trolley into the two-wheeled bag trolley, the handle end of the main frame needs to be pivoted upward about the axis of the running wheels, wherein the handle section of the auxiliary frame is pushed into the displacement guide due to the linkage guide and the auxiliary frame is pivoted relative to the main frame until the end position for the two-wheeled bag trolley operation is reached.

[0007] In the end position of the auxiliary frame for the two-wheeled bag trolley operation, the auxiliary frame can be locked against twisting relative to the main frame in order to prevent an unintentional outward pivoting of the auxiliary frame. BRIEF DESCRIPTION OF DRAWINGS

[0008] Examples of the application are shown in the drawings. In the drawings:

[0009] Figure 1 A side view of the two-wheeled bag trolley of the application is shown,

[0010] Figure 2 An auxiliary frame view of the two-wheeled bag trolley is shown,

[0011] Figure 3 A proportionally smaller side view of the two-wheeled bag trolley in an intermediate position when converting into a four-wheeled trolley is shown,

[0012] Figure 4 A likewise proportionally smaller side view of the two-wheeled bag trolley when converted into a four-wheeled trolley is shown. DETAILED DESCRIPTION

[0013] The two-wheeled bag carrier according to the application comprises a main carriage 1 which has a pick-up shovel 2 at the foot end and two running wheels 3 on the side opposite the pick-up shovel 2. The main carriage is provided on the running wheel side with a handle 5 and on the opposite handle end 4 of the main carriage 1 with displacement guide means 6 for an auxiliary carriage 7, which displacement guide means 6 each consist of two guide sleeves 8 for the two frame legs of the auxiliary carriage 7. These guide sleeves 8 are rotatably mounted on the handle end 4 of the main carriage 1 about a pivot axis 9 parallel to the axis of the running wheels 3. The auxiliary carriage 7 is thus freely slidable in the displacement guide means 6 between an insertion end position, which corresponds to the two-wheeled bag carrier state, as shown in Figure 1 and Figure 2 and a retracted end position, which corresponds to the four-wheeled trolley state, in which the steering wheel 10 arranged on the foot end of the auxiliary carriage 7 is located below the main carriage 1, as shown in Figure 4 In the two-wheeled bag carrier state, the steering wheel of the auxiliary carriage 7 is in a rest position above the running wheels 3.

[0014] Between the main carriage 1 and the auxiliary carriage 7, a connecting rod 11 is provided, the axes of articulation 12, 13 of which are parallel to the pivot axis 9 of the auxiliary carriage 7. The axis of articulation 13 between the auxiliary carriage 7 and the main carriage 1, which is arranged above the steering wheel 10 in the two-wheeled bag carrier state, serves to lock the auxiliary carriage 7 to the main carriage 1, the main carriage 1 for this purpose forming a receiving slot 14 for the axis of articulation 13. The axis of articulation 12 between the main carriage 1 and the connecting rod 11 is located approximately midway between the pivot axis 9 and the axis of articulation 13 in the two-wheeled bag carrier state, as shown in Figure 1 .

[0015] In order to convert the two-wheeled bag carrier into a four-wheeled trolley, firstly, from Figure 1 the axis of articulation 13 is loosened from the receiving slot 14, and then the auxiliary carriage 7 can be pivoted outwards about the pivot axis 9 from the main carriage 1. The connecting rod 11 forms a forced guide for the auxiliary carriage 7 during this process, both in terms of sliding movement and in terms of pivoting movement dependent on the sliding movement. In particular due to the weight load of the auxiliary carriage 7, the connecting rod 11 is loaded with a gravitational torque, which counteracts the pivoting outwards of the auxiliary carriage 7, so that the auxiliary carriage 7 is displaced in dependence on the tilting movement of the main carriage 1 about the axis of the running wheels 3 thereof in a controlled manner for the conversion into a four-wheeled trolley until the steering wheel 10 of the auxiliary carriage 7 rests on the ground, thus forming a support for the auxiliary carriage 7. Due to the ground support of the auxiliary carriage 7, by pivoting thereof about the axis of articulation 12, the end position for the four-wheeled trolley can be reached, as shown in Figure 4 . The pivoting adjustment of the auxiliary carriage 7 is simple, since the handle section of the auxiliary carriage 7, which is provided with a handle 15, projects upwards out of the main carriage 1 in freely accessible manner by means of the displacement guide means 6.

[0016] The pull-out stroke of the auxiliary carriage 7 in the terminal position, in which a triangular connection is obtained through the articulated axes 12, 13 of the connecting rod 11 and the pivot axis 9, which makes the auxiliary carriage 7 constitute a rigid support with respect to the main carriage 1 forming the support platform, is limited by the stop 16 cooperating with the guide sleeve 8, which is a prerequisite for the simple handling of the four-wheeled trolley through the handle section of the auxiliary carriage 7.

[0017] To convert the four-wheeled trolley into a two-wheeled bag trolley, the handle end 4 of the main carriage 1 is lifted in the opposite order, so that the guide sleeve 8 of the main carriage 1 is lifted from the stop 16 of the auxiliary carriage 7 and slides along the auxiliary carriage 7, while the auxiliary carriage 7 is pivoted to the main carriage 1 due to the connecting rod guide until the terminal position corresponding to the two-wheeled bag trolley state is finally reached, in which the auxiliary carriage 7 is again locked with the main carriage 1.

Claims

1. A two-wheeled bag transport trolley convertible into a four-wheeled trolley, comprising a main frame (1), an auxiliary frame (7), a displacement guide device (6) for the auxiliary frame (7), and a connecting rod (11) between the main frame (1) and the auxiliary frame (7), wherein the main frame (1) has a pick-up shovel (2) at a foot end and two running wheels (3) on a side opposite to the pick-up shovel (2), the auxiliary frame (7) supports at least one steering wheel (10) in the foot area, the displacement guide device (6) is pivotable at the handle end (4) of the main frame (1) about a pivot axis (9) parallel to the axis of the running wheel (3), the connecting rod (11) is hinged to the main frame (7) in the foot area of ​​the main frame about an axis (13) parallel to the pivot axis (9), and is characterized in that The auxiliary frame (7) is guided in the displacement guide device (6) so as to be freely slidable between two end positions limited by stops, one of the two end positions determining a two-wheeled bag transport trolley state and the other end position determining a four-wheeled trolley state, and the connecting rod (11) is fixedly and pivotably supported on the main frame (1).

2. The two-wheeled bag transport trolley according to claim 1, characterized in that: The auxiliary frame (7) can be locked with the main frame (1) in a rotationally anti-locking manner in the two-wheeled bag transport trolley state.

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